What's the Deal with Brisbane Tap Water? [2022 Update]
UPDATE (11/01/22): Brisbane residents have been reporting unpleasant, “earthy” tasting, murky, smelly water in recent days. “This is due to an increase in naturally occurring organic compounds in the raw water supply entering our Mount Crosby Water Treatment Plant following recent weather conditions,” Seqwater has said in a report with the ABC.
Despite the unpleasant taste, appearance and smell, this water is still within Australian Drinking Water Guidelines. Seqwater is looking to improve this, but this long period of reduced water quality could stick around for a few weeks.
Every state likes to brag about their local drop, but how does Brisbane tap water compare to the rest of the nation? We’ll be focusing on South East Queensland Water, Seqwater, and Urban Utilities, who are the major players in Brisbane’s water supply and distribution.
Where Does Brisbane Water Come From?
Seqwater is the region’s bulk water supplier that provides nearly 150,000 megalitres (ML) of drinking water alone in South East Queensland. This drinking water comes from 107 reservoirs and is delivered through 9,500 km of water mains.
Urban Utilities, Brisbane’s water service provider, supplies 136,000 ML of water in total to its service area. That’s over 50,000 Olympic-sized swimming pools!
50% of Brisbane’s drinking water supply comes from Wivenhoe Dam, according to Mike Foster from Seqwater. If filled to capacity, this dam can hold 1.165 million megalitres of water!
After the major impact of the Millenium drought in the 2000s, Seqwater implemented a water grid. This allows the transport of treated water to areas that need it most to help bolster their water supply in times of need.
The desalination plant on the Gold Coast acts as a backup source of water for the water grid. The plant can supply 133 ML of water per day at full capacity.
The Use of Recycled Water
If drought conditions push dam levels below 40%, recycled water also comes into play. In combination with recycled water from the Western Corridor Recycled Water Scheme, this accounts for over a third of the entire region’s water demands.
Water levels at Wivenhoe Dam haven’t been this low since the Millennium drought in 2009. As of August 1st, it is sitting at 41.8% capacity. If water levels of the region’s dams combined drop to 50% or less by September 2021, water restrictions will potentially be put in place. Current water use per person is 20-25 litres more per day than what dam managers would like according to the ABC.
The Facts About The Water Treatment Process in Brisbane
Water from Wivenhoe Dam is sent to the Mount Crosby water treatment plant. Raw water is treated so it is safe to drink and delivered to homes around Brisbane.
When the water arrives at the treatment plant, it contains soil, pollutants, debris, microorganisms and more that need to be removed. To be considered safe to drink, the water from treatment plants must meet Australian Drinking Water Guidelines.
A thorough treatment process at Mount Crosby follows a number of water treatment steps.
Coagulation
A coagulant is added to the raw water, typically aluminium sulphate. The water is mixed and reacts with the coagulant to form a thickened mass of particles.
The water pH must be between 6.8 and 7.2 for the next step and so the treatment plant tests and adjusts the pH here.
Raw water at the Mount Crosby treatment plant is often very turbid, making this step essential in the treatment plants’ process.
Flocculation and Sedimentation
The mass of particles formed during the coagulation step forms a floc. These clump together and form heavier masses.
The raw water and floc move into two sedimentation basins. The floc particles bind together and form a sludge that sinks to form sediment on the bottom of the basin floor.
Workers in water treatment plants regularly vacuum the floor to remove the sediment and transport it to a waste sludge pool.
Filtration
With the sludge removed, the water treatment plant filters the water. Mount Crosby starts with dissolved air filtration – a process where they inject a pressurised stream of water containing oxygen, causing bubbles to rise up from the floor.
Floc particles cling to the bubbles, floating to the surface to create a floating sludge blanket, which operators regularly remove to leave behind clarified water. While this water might look just like what comes out of our tap, it still has two more steps before it meets drinking water quality guidelines.
Disinfection and pH Correction
Before any water leaves the Mount Crosby water treatment plant, it undergoes disinfection and pH correction:
- Chlorine kills microorganisms, bacteria and viruses
- Lime corrects the pH for human consumption and prevents corroding or rusting the pipes during transportation
- The addition of fluoride acts a dental health measure
They pump this water to reservoirs at Cameron’s Hill and add chloramine to prevent harmful microorganisms from growing while they transport the water to Brisbane residents. This process ensures your Brisbane tap water is perfectly safe to drink once it leaves your taps.
Brisbane Water Quality Tests
Australia has a strict set of regulations for drinking water quality – the Australian Drinking Water Guidelines. These guidelines undergo regular updates to align with the most stringent standards and current scientific evidence.
The authorities check for safe levels of:
- arsenic
- chlorine
- fluoride
- lead
- nickel
- trihalomethanes
The aesthetic categories include:
- colour
- pH
- temperature
- total dissolved solids
- total hardness
- turbidity
Authorities designed these guidelines to protect the health of Australian residents. Although not mandatory, most water suppliers and providers willingly comply with them.
Is Brisbane Tap Water Safe to Drink?
Yes – tap water in Brisbane is perfectly safe to drink and meets all the Australian Drinking Water Guidelines. Urban Utilities received only 209 complaints about drinking water in 2020-21, 80 fewer than the previous year!
Seqwater and Urban Utilities uphold their commitment to providing Brisbane residents with high-quality, safe drinking water. They action any anomalies outside of these guidelines immediately. In addition, they routinely test to assess the quality and safety of the water. Brisbane’s water quality is only on the way up, with water authorities also future-proofing supplies with alternative water supplies such as recycled water.
If Brisbane tap water quality still concerns you, you can install a water filter that will ensure the water you are drinking is clean. Alternatively, fill up a water filter jug with tap water and use this as drinking water.
Wonder how Brisbane’s tap water compares to other capital cities? We’ve also put Perth and Adelaide drinking water quality to the test!
Published: 2021-04-09